>> reporter: and kelly, secretary of defense, leon panetta says he doesn't know if the two tunisian men are actually tied to al-qaeda, but he does know that the u.s. is not going to stop until they hold whoever murdered those americans in benghazi is held responsible for their terrible crimes. >> we are following up on what i see the arrest that has been made. we're doing everything possible to make sure we go after those involved in the attack in libya. as the president has said. our goal is to make sure that we bring those involved to justice. >> reporter: five days after those four americans were murdered in that deadly raid on our consulate. u.s. ambassador susan write says it might have been a spontaneous attack and it might not have been terrorism and at the time she says she relied squarely on the intelligence community provided to her and she says the intelligence community's best ajestment as of the date of her television appearances, that's not good enough for senators who say in a letter of their own, either the obama administration is misleading congress and the american peo